Double-acting hydraulic jack



Pebl. 5, 1952 R, J, STEINHOFF 2,584,820

DOUBLE-ACTING HYDRAULIC JACK Filed May 1, 1947 2 SHEETS- SHEET 1 /29 25 f I6 l5 N l y 4 2 &3` ".7 2

43'/ 44 477 l l] INVENTOR. 4s

-48 Raymmmd J. Siemhmff ATTE! RN EYB Feb- 5, 1952 R. J. STEINHOFF DOUBLE-ACTING HYDRAULIC JACK 2 SHEETS--SHEET 2 Filed May l, 1947 INVENTOIR. Raymmmjl Stemhmff ATTD RN EYB Patented Feb. 5, 1952 UNITED STATES PATENT GFFICEv mountainous@ minimum: :Aon Raymond J. Steinhof, Alhambra, Calif. minnen Mia? i, y1947, yserai No, 745,276

(ci. eosz) g i l Glaim. l

This invention relates to an all-purpose double acting jack.

Itis an object of the present invention toprofvide a jack motor of this type which has 'attachi ing portions thereon to which can be connected rods or other elements to be operated Vupon by the jack.

Other objects of the present invention are to provide a self-contained pump and jack con struction wherein the jack itself will provide the reservoir for the oil to be pumped by the pump located on the side of the casing' and wherein there is disposed within the casing telescoping parts adapted lto be extended `or retracted ldepending upon the direction to which a two Way valve has been turned and wherein the oil will be conlipletely contained within the casing of the Jac Another object of the present invention is to provide within a hydraulic double acting jackan expansible reservoir for containing the oil tol be extended between the parts to `be extended and wherein within this reservoir is a piston backed up by a spring adapted to keep a pressure on the oil within this reservoir. 1

Other objects of the present invention are' to provide a hydraulic double ,acting jack which is of simple construction, inexpensive to nianufac ture, easy to voperate and eiicierit in operation.

For other objects and forl a better understand?- ing of the invention, rference' may be hadA to thefollowing detailed description taken in e'nnection with the accompanying drawing, in which ,o

Fig. 1 is an elevational view of a double acting jack with portions broken away and shown `-in section in order to show the internal partsk of the jack motor and of the pump attached to the jack motor casing and extending laterally therefrom, v

Fig. 2 is a transverse cross-sectional view taken on line 2-2 of Fig. 1, 1.

Fig. 3 is a transverse cross-sectional view taken on line 3-3 of Fig. 1,

Fig. 4 is a cross-sectional view of the twoway valve with the valve element turned to one position,

Fig. 5 is a cross-sectional view of the two;.-way valve with the valve element turned to another position,

Fig. 6 is an elevation and fragmentaryview of one of the one way ball valve fittings which are inserted through the casing from the exterior thereof,

Fig. 7 is a diagrammatic view of the system bore 38 of an inner piston member 39 screw with the two valve turned to one posit-ien andwith the pump operating to remove oil from the reservoir to the parts to be extended.

Referring now particularly to Fig. 1, I8 repre-i sente the movable cylinder of my double acting back motor on which there is a lug projection II. To this" lug projection II there is pivotally connected a pump handle l2 adapted to be worked upand down and to which there iseond nested a pump plunger I3 extending upwardly to a pump cylinderill projected downwardly from a laterally' extending portion I5 which is in turn screw threaded `to the cylinder I0 at one end thereon as' indicated at I6. As the pump .handle l2 is moved down,- oil is drawn' into the pump cyl inder I4. As the pump handle is raised the oil will be forced outwardlyof the 'same under' pres suie.A The cylinder I8 serves as the principalmo'f torhainber for eil. This chamber is indicated atl'! and oi-l is fnivd therefrom through tube i8 entering the cylinder at I9 and connected with the other part of the cylinder I9 asindli cated at 2|. Oil entering at 2| is passed to the two way valve i2 which is adjustable by a nandle portion 23 extending from the sideof the cylinder. Ii the' valve 22 is moved to one position as illustrated in Fig'. 7, oil will pass through a passa-ge 24 to a reservoir 25. Within this res# ervoir 25 is `a piston 26 backed up by alc'onical 21 andadaptd to maintain a pressure upontlie oil Within this' vreiseri/oir 25 so lthat the fluid will be kept under pressure. The passage Y 24 is within a block or head 28 threaded into one end of the cylinder I0. The reservoir is provided by the fitting 29 screw threaded into the same end of the cylinder and against the threaded block 28. This fitting 29 has a threaded hole 3| serving as means by which the jack can be attached to a rod element to which work is to be imparted.

From the reservoir 25 oil passes through a passage 32, a one way check valve 33 and passage 34 to pump cylinder I4. On the upward movement of the plunger I3 of the pump, oil will be forced to aone way valve fitting 35, arcuate shaped passage 36, two way valve 22, passage 31 to central threaded as indicated at 4I to the block 28. Oil will be delivered through the bore 38 to the opposite end of the piston 39 and will react against a block 42 screw threaded into an annular piston or ram 43 surrounding the piston 39. A piston packing cup 44 is xed to the end of the piston 39. As pressure is built up in a motor chamber 45 in the end of the ram 43, the ram 43 will be projected out of the movable cylinder III. A packing cup 46 is disposed between the ram 43 and the interior of the movable cylinder I0. This packing cup is retained in place by locking plates 41 and 43. A packing gland 5I may be located in the locking plate 48. The plug 42 also has a threaded hole 52 by means of which the jack can be connected to a threadedl rod. Port 60 serves as an air vent leading from the space between ram 43 and head 28 through cylinder I0 to the atmosphere.

The ball valve ttings are connected to the block 28 from the movable cylinder III and are constructed as shown more clearly in Fig. 6. The

ball valve as shown in Fig. 6 includes an opening or chamber 55 in which is disposed a ball 56 and a spring 51 for urging the ball against a seat 58. Oil, upon passing the ball, will enter the cham-- ber 55 and pass outwardly through opening v59. If the jack is to be retracted, the two way valve 22 is turned to the position shown in Fig. 5. The operation will then be reversed. Fluid will then flow from the motor chamber 45 toward the motor chamber I1. The oil under reversed operation will pass from the motor chamber 45 through the centralbore 38 of the piston 39 and passage 3,1 to the valve 22 then through passage 24 to the reservoir 25. This is due to the fact that the oil passes through passage 32, from the reservoir 25 to the check valve 33 and passage 34 to pump cylinder I4. Operation of the plunger I3 will force the oil to valve tting 35, passage 36 and two-way valve 22, through tube I8 to motor cylinder I1. Pressure inthe motor cylinder II forces the head of the ram upwardly and retracts the block 42 fastened thereto. The pump I4 will be actuated and a pulling force will be placed upon' the ends of the jack and will pull together any parts connected to the same. The reservoir 25 will receive the oil on its return passage and thel piston and spring device therein will maintain'the oil leaving the reservoir 25 under pressure.

`While various changes shall be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claim. .'"Iclaim: An all-purpose dou le acting jack comprising a lmovable cylinder, a block xed to one end of the movable cylinder, a piston anchored to the block and extending into the movable cylinder, a ram surrounding the piston. said ram being spaced from the inner wall of the movable cylinder to provide a motor chamber within the movable cylinder, said ram being slidable out of the movable cylinder, a reservoir associated with the movable cylinder for at first receiving the oil leaving the motor chamber, spring pressure means within the reservoir placing the oil therein under pressure, a second motor chamber in said ram, a pump associated with the movable cylinder to draw oil from the reservoir and to force the same to the second motor chamber between the piston and the ram to extend the same relative to one another, and said ram being retracted by returning the oil to the motor chamber between the ram and the movable cylinder, and the block secured to the piston having passages for receiving oil from the reservoir for passage to the pump and for the return of the oil from the pump under pressure for deliveryto the second motor chamber between the piston and ram, said piston having a central bore extending downwardly therethrough and said central bore being in communication with the passages within the block, said reservoir being disposed on the end of the movable cylinder adjacent to the block and comprising further a member screw threaded into the movable cylinder and said member having an attaching portion connecting the jack to a part to be worked by the jack and said ram having a member adapted for the attachment of the jack to a part to be operated by the jack, and a twoway Valve connected with the block 'and the passages therein'for reversing the ow of the oil. RAYMOND J. STEINHOFF.

REFERENCES CITED f fIheollowin-g references are of record in the iileof this patent:

UNITED STATES vPTE'N'I'S Great Britain Jan. 6. 1931 

